There are four future raptures, not one. In the Scriptures there are five raptures altogether. The first involving the Lord Jesus Christ took place before the inauguration of the church about two thousand years ago. In the last seven years of the current dispensation of grace that is about the same as the Jewish 70th heptad of seven years, there will be four raptures.
The first is the rapture of the church, which involves the living and the dead in Christ. The second is the rapture of 144,000 sealed Jewish Evangelists. The third is the rapture of God’s Two Special Witnesses. The fourth and last is the rapture of Tribulation Martyrs.